Microbiology Exam 3 - Rio Salado Questions With Complete Solutions
According to the data provided, which organism most easily causes an infection?
E.coli- 20
Legionella pneumonphila- 1
Shigella- 10
Treponema pallidum- 57 - ANSWER-Legionella Pneumonphila
According to the data provided, which organism causes the most severe disease?
E.coli- 20
Legionella pneumonphila- 1
Shigella- 10
Treponema pallidum- 57 - ANSWER-The answer cannot be determined based on the
information
A 77-year-old man presented to the emergency department with abdominal pain. He was
drowsy and confused when roused and was peripherally cold with cyanosis. The abdomen was
tense and distended. A CT scan of the abdomen showed extraluminal gas and suspected
extraluminal feces consistent with a perforated sigmoid colon.
He was treated with intravenous antibiotics and taken to the operating room for laparotomy.
During this procedure, gross fecal peritonitis from a perforated sigmoid colon was confirmed;
resection of the sigmoid colon with closure of the rectal stump and creation of an end
colostomy was performed.
What is the predominant normal flora found in the sigmoid colon? - ANSWER-Gram negative
rod
Upon arival to the ER, the man from the previous question had an extremely (life-threatening)
low blood pressure and a very fast heart rate.
What is the most likely condition that the patient is experiencing? - ANSWER-Septic shock
What is the underlying cause of this man's septic shock? (exotoxins or endotoxin) - ANSWER-
endotoxin
What is the name of the process that occurs between DNA and RNA? - ANSWER-transcription
, Click on the structure that correlates with a phenotype. - ANSWER-protein
Click on the structure that correlates to the genotype of the cell. - ANSWER-DNA
What type of genetic flow of information is occurring? - ANSWER-horizontal gene transfer
Mutations occur to give individuals reproductive advantages over other individuals. - ANSWER-
False
Ciprofloxacin inhibits DNA gyrase.
Thinking about microbial genetics, what process is inhibited by Ciprofloxacin? - ANSWER-DNA
replication
Erythromycin binds to the 50S subunit of a ribosome.
Thinking about microbial genetics, what process is inhibited by erythromycin? - ANSWER-RNA
translation
The following table shows the ID50 for Staphylococcus aureus in wounds with and without the
administration of ampicillin before surgery. Based on the data, the administration of ampicillin
before surgery
-Staphylococcus aureus- wound - <10
-Staphylococcus aureus- wound + ampicillin
=300 - ANSWER-decrease the risk of staphylococcal infection
The characteristics displayed by an organism in any given environment is its - ANSWER-
phenotype
The source of variation among microorganisms that were once identical is - ANSWER-mutation
antibiotics - ANSWER-provide an environment in which preexisting mutants survive
DNA transfer by conjugation is more efficient in a liquid medium setting, subjected to very mild
agitation (stirring), rather than on an agar plate format. Why? - ANSWER-Direct cell-to-cell
contact is required for this process, and this is more likely to be achieved in the fluid liquid
format than on an agar plate (especially for relatively non-motile types of bacteria).
Which of the following does not apply to plasmids? - ANSWER-they are essential for growth
The origin of the penicillin-resistant strain Neisseria gonorrhoeae probably is due to: - ANSWER-
spontaneous mutation
According to the data provided, which organism most easily causes an infection?
E.coli- 20
Legionella pneumonphila- 1
Shigella- 10
Treponema pallidum- 57 - ANSWER-Legionella Pneumonphila
According to the data provided, which organism causes the most severe disease?
E.coli- 20
Legionella pneumonphila- 1
Shigella- 10
Treponema pallidum- 57 - ANSWER-The answer cannot be determined based on the
information
A 77-year-old man presented to the emergency department with abdominal pain. He was
drowsy and confused when roused and was peripherally cold with cyanosis. The abdomen was
tense and distended. A CT scan of the abdomen showed extraluminal gas and suspected
extraluminal feces consistent with a perforated sigmoid colon.
He was treated with intravenous antibiotics and taken to the operating room for laparotomy.
During this procedure, gross fecal peritonitis from a perforated sigmoid colon was confirmed;
resection of the sigmoid colon with closure of the rectal stump and creation of an end
colostomy was performed.
What is the predominant normal flora found in the sigmoid colon? - ANSWER-Gram negative
rod
Upon arival to the ER, the man from the previous question had an extremely (life-threatening)
low blood pressure and a very fast heart rate.
What is the most likely condition that the patient is experiencing? - ANSWER-Septic shock
What is the underlying cause of this man's septic shock? (exotoxins or endotoxin) - ANSWER-
endotoxin
What is the name of the process that occurs between DNA and RNA? - ANSWER-transcription
, Click on the structure that correlates with a phenotype. - ANSWER-protein
Click on the structure that correlates to the genotype of the cell. - ANSWER-DNA
What type of genetic flow of information is occurring? - ANSWER-horizontal gene transfer
Mutations occur to give individuals reproductive advantages over other individuals. - ANSWER-
False
Ciprofloxacin inhibits DNA gyrase.
Thinking about microbial genetics, what process is inhibited by Ciprofloxacin? - ANSWER-DNA
replication
Erythromycin binds to the 50S subunit of a ribosome.
Thinking about microbial genetics, what process is inhibited by erythromycin? - ANSWER-RNA
translation
The following table shows the ID50 for Staphylococcus aureus in wounds with and without the
administration of ampicillin before surgery. Based on the data, the administration of ampicillin
before surgery
-Staphylococcus aureus- wound - <10
-Staphylococcus aureus- wound + ampicillin
=300 - ANSWER-decrease the risk of staphylococcal infection
The characteristics displayed by an organism in any given environment is its - ANSWER-
phenotype
The source of variation among microorganisms that were once identical is - ANSWER-mutation
antibiotics - ANSWER-provide an environment in which preexisting mutants survive
DNA transfer by conjugation is more efficient in a liquid medium setting, subjected to very mild
agitation (stirring), rather than on an agar plate format. Why? - ANSWER-Direct cell-to-cell
contact is required for this process, and this is more likely to be achieved in the fluid liquid
format than on an agar plate (especially for relatively non-motile types of bacteria).
Which of the following does not apply to plasmids? - ANSWER-they are essential for growth
The origin of the penicillin-resistant strain Neisseria gonorrhoeae probably is due to: - ANSWER-
spontaneous mutation
